
Interestingly enough, one article says that it was likely an accident that she was so well preserved. The coffin was flooded with water, preventing bacteria from breaking down the body.
pretty. freaking. amazing.
see full article here:
http://www.telegraph.co.uk/news/picturegalleries/worldnews/8361635/Archaeologists-find-Ming-Dynasty-mummy-in-China.html
and here:
http://www.dailymail.co.uk/sciencetech/article-1362957/700-year-old-mummy-road-workers-east-China-excellent-condition.html